Introduction of Glyoxylate Bypass Increases Hydrogen Gas Yield from Acetate and l -Glutamate in Rhodobacter sphaeroides

As an alternative to fossil fuel, H2 is a promising renewable energy source. Although photofermentative H2 production from acetate is key to developing an efficient process of biohydrogen production from biomass-derived sugars, H2 yields from acetate andl -glutamate byR. sphaeroides have been reported to be low. In this study, we observed that in addition to the endogenous EMC pathway, heterologous expression of the glyoxylate bypass inR. sphaeroides markedly increased H2 yields from acetate andl -glutamate. Therefore, this study provides a novel strategy for improving H2 yields from acetate in the presence ofl -glutamate and contributes to a clear understanding of acetate metabolism inR. sphaeroides during photofermentative H2 production.